Veterinarian&#39;s castrating-knife.



E. L. WATSON.

VETERINARIAN'S GASTRATINGKNIFE. APPLIOATJION FILED MAB.3,1911.

1,037,693. Patented Sept. 3, 1912.

wilnesses:

COLUMBIA PLANOORAPH 60.. WASHINGTON D. c.

EDWARD L. WATSON, OF DALLAS, $OUTH DAKOTA.

VETERINARIANS GASTBATING-KNIFE.

Specification of Letters Patent.

Patented Sept. 3,1912.

Application filed March 3, 1911. Serial No. 612,170.

To all whom it may concern:

Be it known that I, EDWARD L. lVA'rsoN, a citizen of the United States, residing at Dallas, in the county of Gregory, State of South Dakota, have invented a new and useful Veterinarians Castrating-Knife Designed for Use in Standing Operations and lVhich May Also be Used for other Operations, of which the following is a specification.

My invention relates to an improved form and shape of knife, having a blade of improved shape, set upon the handle in an improved relative position.

The object of my invention is to provide i a knife which will facilitate castration, j

especially when the subject is ina standing position, by the following improvements: 1st, by positioning the blade on the handle at such an angle that the hand of the operator will be in a natural and easy position when making the incision; 2d, by so and handle as to give shaping the blade grasp of the knife and the operator a firm prevent slipping and turning in the hand the blade and placing it 3d, by so shaping on the handle at such an angle as to give more room for the hand of the operator in performing the operation; fth, by providing a blade of such shape and so posij tioned on the handle as to lessen the danger of the operator cutting himself; 5th, by providing a blade of such shape and positioning it at such an angle on the handle that in making the incision the cutting edge of the blade j I will be at all times parallel to the tissues and so that in making the incision the point of the blade will not be raised; 6th, by providing a blade of such shape and positioning it on the handle so that the incision necessary to the operation may be made at a single stroke of the knife and by a single rotary motion of the hand from the wrist. I attain these objects by means of an in.- strumentconstructed as shown in the annexed drawing, in which- Figure 1 is a side view of the instrument. Fig. 2 is an edge view, with the blade foremost.

The instrument is constructed of asingle piece of steel, as illustrated in Figs. 1 and 2.

E is the handle.

D is a loop formed by the inverted end of the handle, in which the little finger of the operator rests and which, together withj the brace afforded the thumb by the concave back of the knife blade, enables the operator to obtain a firm grasp of the instrument.

A indicates the heel of the knife blade,

which projects forward from the handle E forming an approximate right angle therewith. The knife blade, which curves across the medial line of the implement and eX- tends back of the handle E, terminates in the knife blade point B. The line from A to B is the involute cutting edge of the knife blade.

C is the evolute back of the knife blade, concaved to receive the ball of the thumb as a brace when the knife is in the hand of the operator.

The blade of the instrument, as illustrated in Fig. 1, is positioned upon the handle at an angle of about 225 degrees, reference being had to the angle that would be formed by a medial line drawn through the knife blade from its point B to an extended medial line of the handle. The lower portion of the blade, about half, projects in front of the handle so that an angle of about 45 degrees would be formed by a medial line drawn through the knife blade from the heel A to an extended medial line of the handle. The positioning of the knife blade so as to project in front of the handle and beyond the fingers of the operator affords him more room for his hand between the thighs of' the animal.

The involute and nearly semi-circular shape of the cutting edge of the blade, together with the positioning of the blade upon the handle at the angle illustrated in Fig. 1, enables the operator to make the incision by a single rotary motion of the wrist, rotating the blade forward and downward, without raising the point of theblade so as to endanger the hand of the operator.

I claim as new and useful in this invention:

1. A veterinary surgical instrument comprising a hook-shaped handle and a concavo-convex knife blade formed integrally therewith and so positioned upon the handle that the heel of the blade projects in front of the handle at an angle of about so degrees and the point of the blade extends back of the handle at an angle of about 225 degrees, with the handle positioned under approximately the center of the blade and so disposed that the hook portion of the handle provides a brace for the little finger and coacts with the concave back of the knife blade as a brace for the thumb, Whereby the knife may be grasped and rotatively operated in the manner hereinbefore specilied.

2. A veterinary surgical instrument comprising a handle, a knife blade having a sharpened convex edge and a dulled concave back, the said knife blade being positioned upon the handle angularly so that heel of the blade projects in front of and the point of the blade extends back of the handle with the handle under approximately the center of the blade, and a loop on the handle, so disposed as to provide a brace for the llttle finger and to coact with the i EDlVARD L. XVATSON. \Vitnesses J. D. KELLER, M. C. BECK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

